The faces on the middle-aged couple were etched in grief as they sat in federal court on Long Island — somber in every way except for their startling biker-chic duds and wild and tousled ’80s-style hair.

Since Valentine’s Day, rocker Dee Snider, 55, the frontman of the heavy-metal band Twisted Sister, has sat beside his petite blond wife, Suzette, 50, at pretrial hearings for the man accused of her younger brother’s grisly mob-style murder.

“My brother’s murderer sits in the court room with a smile on his face,” she tweeted on Feb. 15.

“I can’t wait until we get justice and the smile is on my face.”

The Aug. 13, 2003, slaying of 34-year-old Vincent Gargiulo has haunted the family, who live in a mansion in a gated community in East Setauket, LI.

“It’s an incredible feeling of frustration to know who is responsible for the death of a loved one and not be able to do anything about it,” Snider said on an episode of “Celebrity Ghost Stories” on the Biography Channel — one of the few times he’s talked publicly about the case.

“My wife’s torment over thinking about this guy she knew had murdered her brother affected her on an emotional level, a physical level, and we hurt as a family as well.”

Snider has said his brother-in-law, who’d done three stints in jail, had begun to turn his life around before he was shot between the eyes.

“Eighteen years ago, he walked away from a life of crime, and he never looked back,” he told reporters after the murder.

“He was a great brother to my wife, a great brother-in-law and a great uncle to my kids,” he told The Post at the time.

Gargiulo was killed after he and business partner Christian Tarantino fell out over the fortunes of their Manhattan gym, prosecutors claim.

Prosecutors say Gargiulo had a tape recording in which Tarantino allegedly discussed two slayings connected with a 1994 armored-car heist. Tarantino’s lawyers claim the tape is “not authentic.”

The pretrial hearings ended last week and the murder and conspiracy trial is scheduled to begin March 22.

On the first day of hearings in federal court in Central Islip, Snider’s son Cody sat with his parents.